This invention relates to improved processes for preparing 5-substituted amino-3-oxo-4-(substituted phenyl)-2,3-dihydrofuran and 2,3-dihydrothiophenes. The products are especially useful as herbicides.
Commonly assigned U.S. application Ser. No. 607,610, filed May 9, 1984, Carl E. Ward, discloses herbicidal compounds having the generic formula: ##STR1## wherein R, R.sup.1, R.sup.2, X and Y can be certain substituents as will be subsequently defined.
Also in commonly-assigned U.S. application Ser. No. 623,805, filed June 22, 1984, C. E. Ward discloses compounds having the formula: ##STR2## wherein R, R.sup.1, R.sup.2, X and Y can be certain substituents as will be subsequently defined.
The disclosures of said U.S. applications Ser. Nos. 607,610 and 623,805 are hereby incorporated by reference in their entirety.
In accordance with the teachings of theses applications, the compounds of Formulas I and II wherein one or both of R.sup.1 and/or R.sup.2 are other than nydrogen are prepared by a fairly complicated alkylation of the corresponding primary or secondary amine of Formulas I and II.
The Journal of Organic Chemistry, Vol. 49, p. 228 (1984) describes the preparation of 1-aryl-2-amino-5-oxocyclopent-1-ene via the reaction of ammonia or ammonium hydroxide with 1-aryl-2-chloro-5-oxocyclopent-1-ene. Synthesis p. 902 (1983) describes the amination of certain 1-hydroxy-2-acylethylene derivatives with quaternary acetate salts (e.g., R.sup.4 NH.sub.3 OAc) to yield the corresponding 1-(R.sup.4 -amino)-2-acylethylene derivative. Other aminations are described in Chemiker-Zeitung Vol. 104, p, 302 (1980) and Tetrahedron, Vol. 24, p, 5655 (1968).